The present invention relates to the washing of objects to remove soil therefrom, and is particularly directed at a method for improving the machine washing of clothes made out of woven textiles wherein the make-up water is more or less hard by a process of removing the hardness-forming cations therefrom. The invention involves a method for rapidly decreasing the hardness of the water during the washing cycle without depositing insoluble granular material in the clothes and without interfering with the action of anionic and non-ionic detergents. The invention includes apparatus suitable for performing the process, comprising a specially effective zeolite adapted to remove hardness-forming cations.